Most food/nutrition/snack/energy bars (generally, “food bars”) contain a significant amount of protein-containing ingredients. Typical protein-containing ingredients include soy and whey isolates, which differ in functional properties, such as emulsification, water-binding, and gel strength. Protein ingredients such as soy protein isolate, whey protein, sodium or calcium caseinate, whole milk protein, pea protein, egg albumin and wheat gluten, that exhibit significant viscosity, gel strength, and water-binding properties, positively influence initial texture of the bar.
Bars containing protein ingredients typically harden over their shelf life. Proteins that exhibit high water-binding properties are thought to positively influence the initial texture of the bar, but are believed to have the effect of firming the bar's texture over its shelf life. It is believed that the firming is not caused by water loss per se, but rather, by migration of the water from some ingredients to others, such as from the carbohydrate fraction to the protein fraction. This hardening or firming of the bars is generally thought to be the result of the dual cause of protein aggregation and the formation of crystalline-like structures by the carbohydrate fractions.
A variety of different carbohydrates, such as gums, maltodextrin, and cellulose derivatives, are added to nutrition/snack/energy bar formulations to hold moisture and to modify texture. While those ingredients may be somewhat effective in preventing moisture loss to the environment, their effectiveness in preventing moisture transfer to protein ingredients is minimal. Increasing the amount of carbohydrates, such as maltodextrin, that take on a crystalline-like form upon moisture loss, is believed to enhance the finning effect during shelf life.